Scientists Discover Mutation That May Hold Key to Preventing Type 2 Diabetes
In October 2009, pediatric endocrinologist Dr. Arlene Mercado judged that five-year-old Claudialee Nicanor-Gomez was on track for type 2 diabetes. As we detailed in our October feature, Type Miscast, Claudialee and her mother Irma visited Mercado two more times over the next six months. At the end of each meeting, Mercado repeated the same directive to the mother and daughter: "Diet and exercise." And if Claudialee's blood sugar still continued to rise to the point of full-blown diabetes, Mercado would consider prescribing some medication to enhance the effect of the lifestyle change. Type 2 diabetes approaches you like a train and all you can do is hope you hit the breaks soon enough.
But this treatment paradigm may soon shift. Researchers have discovered a rare gene mutation that may hold the key to preventing type 2 diabetes among those at high risk for the disease.
According to a new study published this month in Nature Genetics, the mutation can lower a person's type 2 diabetes risk by two-thirds. People with the mutation appeared to have slightly lower blood sugar levels and slightly higher amounts of insulin than those without it.
Diabetes stems directly from high blood sugar. And as Claudialee's story illustrated, the impact of a treatment is limited by the accuracy of the diagnosis. Claudialee did not have type 2 diabetes but type 1, which is far more urgent and requires regular insulin injections. The misdiagnosis led to the wrong treatment, which ultimately led to the girl's death in January 2010.
A doctor cannot cure or prevent type 1 diabetes, only limit its damage by quickly identifying it and ordering insulin shots. This version of diabetes arrives so early in a child's life that the child is effectively born with it. In type 1, the immune system kills off cells that produce insulin, the hormone that brings the body's glucose supply to muscle and fat. If the body doesn't get more insulin, the person will die.
Type 2, however, comes slowly. Preventing the disease is a matter of understanding the risk factors associated with it. Obesity is the usual cause. Smoking and sugary eating habits increase the chances. A person's risk grows with his or her age. Certain demographics appear to be more susceptible. In type 2, a person has a lot of insulin, but the stuff just doesn't work. Insulin resistance, doctors call it. A patient can minimize the damage through diet, exercise, and medication.
Next: a possible new medicine to prevent type 2.
The gradual nature of type 2 offers the basis for a potential preventative medicine. The researchers, representing multiple academic institutions, including Harvard and M.I.T., suggested that the existence of the mutation provides scientists a blueprint to create a drug that mimics its effect on the body. The idea is: Give it to those with high risk factors and rising blood sugar, and they may not get diabetes to begin with.
The researchers studied thousands of subjects in Sweden and Finland, comparing diabetes rates among those with high risk factors (older, more obese, smokers) and those with low risk factors.
While examining the high-risk, non-diabetic population, they discovered that some of the people had a mutation that killed a certain gene in pancreas cells. The researchers were initially skeptical of the discovery because that same mutation seemed to increase the risk of diabetes in mice. But examinations of thousands more people subjects showed the same pattern.
Two drug companies, Pfizer and Amgen, provided financing and data to the research team, hoping to turn any discoveries into a profitable drug. Diabetes, after all, is one of the most common diseases in America. It will be years, if not decades, before the benefits of the study reach medicine cabinets, but the researchers envision that the mutation's behavior presents a "therapeutic strategy in [type 2 diabetes] prevention."
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